Windows 11 File Explorer Search treating spaces as "or" instead of "and"...sort of.

I've recently been experiencing some baffling behavior when searching with Windows 11 File Explorer, and wanted to check whether there's an underlying setting or even a known bug causing it. Basically, searching for two partial terms returns results containing both terms as expected, but as soon as a term forms a complete word from the filename of any file in the folder (defined by separation with spaces or underscores), every result including that term is included. Like, say I'm searching for "pizza" along with an ingredient. If I want to search for pepperoni pizza, I need to search for "pepperon pizz", because completing either term will add either every file containing "pepperoni" or every file containing "pizza." This is particularly frustrating because those partial terms cause problems in and of themselves. For example, the above partial search will also return pizzas with pepperoncini because there's no way to exclude it without completing the term and throwing in every food containing pepperoni. Shorter partials cause varying unintended results: "peppe pizz" returns pizzas with pepper, pepperoncini, or pepperoni. "pepper pizz" explodes the results into EVERY file including pepper, pizza or not. "peppero pizz" then immediately contracts them back down to pepperoni or pepperoncini pizzas. Throwing in other search-y things - quotes, "AND", asterisks - doesn't help.

Obviously, I would rather not have to puzzle out how to retrieve the least irritating set of results every time I want to perform a file search, and I'd also rather not reset Windows if I don't have to (especially if it won't make a difference). I've tried restarting Explorer, restarting the computer, and rebuilding the search index. There's a rogue "csc" location that shows up whenever I rebuild the index, but as I understand it this shouldn't matter either way because the indexed location I'm searching is on an external drive, rather than within my user profile. The problem started around the time I installed the 2026-05 Preview Update (KB5089573), but I didn't notice the issue soon enough to say anything very certain where that's concerned. A system restore (from after that Preview Update) didn't help and broke Notepad of all things, so I just reverted it. I'm at a loss, so any help would be appreciated.